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S40.921A ICD-10-CM Code: Unspecified superficial injury of right upper arm, initial encounter

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FY 2026 Apr update / Injury, poisoning and certain other consequences of external causes (S00-T88) / Injuries to the shoulder and upper arm (S40-S49)

S40.921A

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Unspecified superficial injury of right upper arm, initial encounter

Unspecified superficial injury of right upper arm, initial encounter

CMS-HCC V28

0

0

RAF 0

CMS-HCC V24

0

0

RAF 0

ACA/HHS

0

0

RAF 0

ESRD/PACE

0

0

RAF 0

RXHCC

0

0

RAF 0

Code Trumping

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Code Book Path

Official
S40.92Unspecified superficial injury of upper arm
S40.921Unspecified superficial injury of right upper arm
S40.921AUnspecified superficial injury of right upper arm, initial encounter

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for S40.921A in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for S40.921A in this effective period.

Related Child Codes

Official
S40.921DUnspecified superficial injury of right upper arm, subsequent encounter
S40.921SUnspecified superficial injury of right upper arm, sequela

Includes

Official

ICD-10-CM does not list Includes notes for S40.921A in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for S40.921A in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for S40.921A in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for S40.921A in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for S40.921A in this effective period.

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is S40.921A an HCC code?

No. S40.921A is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).

What This Code Means

S40.921A is the ICD-10-CM diagnosis code for unspecified superficial injury of right upper arm, initial encounter. S40.921A sits in the ICD-10-CM chapter for injury, poisoning and certain other consequences of external causes (s00-t88), within the section covering injuries to the shoulder and upper arm (s40-s49).

S40.921A is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

S40.921A is a billable ICD-10-CM code that can be reported on claims but does not currently contribute to a Medicare Advantage member's RAF score under any CMS risk adjustment model (V28, V24, ESRD, or RxHCC). Coders reviewing S40.921A should check whether additional documentation would support a more specific child code in the same hierarchy that does map to a payment HCC, capturing the correct specificity is the highest-impact RAF improvement available within accurate coding.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for S40.921A sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Child Codes

Code Hierarchy

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